copyright · received research attention due to its advantages including high-speed asynchronous...
TRANSCRIPT
© COPYRIG
HT UPM
UNIVERSITI PUTRA MALAYSIA
MAJID HAYAS KAKA
FK 2013 53
DEVELOPMENT OF MULTI-SERVICE CODE FAMILY FOR SPECTRAL AMPLITUDE CODING - OPTICAL CODE DIVISION
MULTIPLE ACCESS SYSTEMS
© COPYRIG
HT UPM
i
DEVELOPMENT OF MULTI-SERVICE CODE FAMILY FOR
SPECTRAL AMPLITUDE CODING - OPTICAL CODE DIVISION
MULTIPLE ACCESS SYSTEMS
By
MAJID HAYAS KAKA
Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia,
in Fulfillment of the Requirement for the Degree of Master of Science
September 2013
© COPYRIG
HT UPM
COPYRIGHT
All materials contained within the thesis, including without limitation text, logos,
icons, photographs and other artwork, is copyright material of Universiti Putra
Malaysia unless otherwise stated. Use may be made of any material contained within
the thesis for non–commercial purposes from copyright holder. Commercial use of
material may only be made with the express prior, written permission of Universiti
Putra Malaysia.
Copyright © Universiti Putra Malaysia
© COPYRIG
HT UPM
ii
DEDICATION
To my:
Beloved parents,
Sisters and brothers,
Beloved wife, Shawnim, and
Daughter and son, Yara and Yar
© COPYRIG
HT UPM
iii
Abstract of the thesis presented to the Senate of Universiti Putra Malaysia in
fulfillment of the requirement for the degree of Master of Science
DEVELOPMENT OF MULTI-SERVICE CODE FAMILY FOR
SPECTRAL AMPLITUDE CODING - OPTICAL CODE DIVISION
MULTIPLE ACCESS SYSTEMS
By
MAJID HAYAS KAKA
September 2013
Chairman: Makhfudzah Bt Mokhtar, PhD.
Faculty: Engineering
In recent years Optical Code Division Multiple Access (OCDMA) technique
received research attention due to its advantages including high-speed asynchronous
low-latency access networking, dynamic bandwidth assignment and secured
transmission. Among several encoding techniques developed for OCDMA systems,
Spectral Amplitude Coding (SAC) is known as a suitable option to provide the
Quality of Service (QoS) in optical communication networks by varying the code
length, weight or both. SAC also has other advantages such as simplicity and lower
cost of system components.
In this thesis, a family of novel spreading sequences is constructed, called a Multi-
Service (MS) code have been proposed for SAC-OCDMA system, to suppress the
MAI consequently mitigate the Phase Induced Intensity Noise (PIIN), accommodate
large number of users and enhanced the optical network capacity as well as offering
service differentiation in optical domain. This proposed code has its own advantage
because it could generate code-words in flexible way by setting variable basic codes
at fixed code weight.
© COPYRIG
HT UPM
iv
The performance of the proposed code is demonstrated via mathematical simulation
and it is shown that with 3.75 THz line width Broadband Source, MS code supports
up to 10 users simultaneously at satisfactory Bit Error Rate (BER) of 10-9
, choosing
code weight of 4 and optimizing number of users per sequence when the bit-rate is
622 Mbps. Furthermore, the results showed that in higher bit-rate e.g. 5 and 10 Gbps,
MS with code weight of 4 supports up to 15 and 7 active users respectively. Thus,
from the results it indicates that MS code does not only preserve the capability of
suppressing MAI, but also improves BER performance due to low cross-correlation
( ) between code sequences. .
Moreover, in the simulation analyses the software, OptiSystemTM
version 10 was
utilized to simulate the MS code system. The effects of various parameters such as
fiber distance, bit rate, received optical power on the SAC-OCDMA system have
been studied and compared, using the MS, Modified Quadratic Congruence (MQC),
Khazani Syed (KS) and Random Diagonal (RD) codes. Based on the simulation
results, performance of MS code outperformed former codes when the number of
basic codes, NB was optimally chosen.
Finally, the MS code was applied to one of the OCDMA applications which is
Triple-Play services (audio, data, and video) with different QoS requirements. The
proposed system used the dynamic basic codes (NB) feature of MS code to provide
different QoS metrics for different users with fixed code weight. It is shown that
optimum performance of specific NB can be obtained with a proper choice of
supportable users. Codes that used lower value of NB always have smaller error
probability. Hence, overall network performance can be improved if the number of
lower NB users is larger in the multimedia applications. Due to the major advantages
of the MS code, with a fewer number of weights, the cost and the complexity of the
system is reduced comparing with other QoS codes. Hereby, MS code seems to be a
good candidate for providing QoS applications.
© COPYRIG
HT UPM
v
Abstrak tesis ini dikemukakan kepada Senat Universiti Putra Malaysia sebagai
memenuhi keperluan untuk ijazah Sarjana Sains
PEMBANGUNAN PERKHIDMATAN-PELBAGAI KOD KELUARGA
UNTUK PENGEKODAN AMPLITUD SPEKTRAL - PEMBEHAGI KOD
AKSES PELBAGAI OPTIK
Oleh
MAJID HAYAS KAKA
September 2013
Pengerusi: Makhfudzah Bt Mokhtar, PhD.
Fakulti: Kejuruteraan
Sejak kebelakangan ini Pembehagi Kod Akses Pelbagai Optik (OCDMA) teknik
mendapat perhatian dalam bidang penyelidikan kerana kelebihannya iaitu akses
rangkaian kependaman rendah dan tak segerak dengan kelajuan tinggi, pembahagian
jalur lebar yang dinamik dan penghantaran yang terjamin. Antara teknik pengekodan
yang dihasilkan untuk sistem OCDMA ialah Pengkodan Amplitud Spektral (MPS)
yang merupakan pilihan sesuai dalam menyediakan QoS rangkaian komunikasi optik
dengan mengubah panjang kod, pemberat atau kedua-duanya. MPS juga mempunyai
kelebihan lain seperti lebih ringkas dan kos komponen sistem yang lebih rendah.
Dalam tesis ini, keluarga sebaran urutan yang baru telah dibina iaitu kod
perkhidmatan-pelbagai (MS) dan telah dicadangkan untuk sistem SAC-OCDMA,
bagi menahan MAI seterusnya mengurangkan Fasa Intensiti Teraruh Bunyi (PIIN),
untuk menampung jumlah pengguna yang tinggi dan meningkatkan kapasiti
rangkaian optik serta menawarkan perbezaan dalam perkhidmatan domain optik.
Kaedah kod yang dicadangkan ini mempunyai kelebihan tersendiri kerana ia boleh
menjana kod-perkataan dalam cara yang fleksibel dengan menetapkan kod asas
berubah pada pemberat kod tetap.
© COPYRIG
HT UPM
vi
Prestasi kod yang dicadangkan ini ditunjukkan melalui simulasi matematik dan ia
menunjukkan bahawa, dengan memilih pemberat kod 4 dan mengoptimumkan
bilangan pengguna setiap urutan pada kadar bit 622 Mbps, MS kod menyokong
sehingga 10 pengguna serentak pada kadar ralat bit (BER) yang memuaskan iaitu
10-9
. Selain daripada itu, keputusan menunjukkan bahawa pada kadar bit yang lebih
tinggi seperti 5 dan 10 Gbps, MS dengan pemberat kod 4 menyokong sehingga 15
dan 7 pengguna aktif. Oleh itu, dari keputusan ini menunjukkan bahawa kod MS
bukan sahaja mengekalkan keupayaan menahan MAI , tetapi juga meningkatkan
prestasi BER disebabkan silang korelasi ( ) yang rendah antara urutan kod.
.
Selain daripada itu, OptiSystemTM
versi 10 telah digunakan untuk mensimulasikan
sistem kod MS. Kesan daripada pelbagai parameter seperti jarak gentian, kadar bit
dan kuasa optik yang diterima pada sistem SAC-OCDMA telah dikaji dan
dibandingkan dengan menggunakan MS, Modified Quadratic Congruence, (MQC),
Syed Khazani (KS) dan Random Diagonal (RD ) Kod. Berdasarkan keputusan
simulasi, prestasi kod MS mengatasi kod terdahulu apabila bilangan pengguna dalam
kod asas, NB telah dipilih secara optimum.
Akhirnya, kod MS telah diaplikasikan kepada salah satu daripada aplikasi OCDMA
iaitu perkhidmatan Triple-Play (audio, data, dan video) dengan keperluan QoS
berbeza. Sistem yang dicadangkan menggunakan ciri kod MS iaitu kod asas dinamik
(NB) untuk menyediakan metrik QoS yang berbeza bagi pengguna yang berbeza
dengan pemberat kod tetap. Selain daripada itu, ia menunjukkan bahawa prestasi
optimum NB boleh dicapai dengan membuat pilihan yang betul dari pengguna yang
dikekalkan. Kod yang menggunakan nilai (NB) yang lebih rendah sentiasa
mempunyai ralat kebarangkalian yang lebih kecil. Oleh itu, prestasi keseluruhan
rangkaian boleh diperbaiki jika bilangan pengguna dengan nilai (NB) yang lebih
rendah adalah lebih ramai di dalam aplikasi multimedia. Dengan bilangan pemberat
yang rendah, jumlah kos dan tahap kekompleksan dapat dikurangkan berbanding
dengan kod QoS yang lain. Oleh yang demikian, MS kod merupakan calon yang
sesuai untuk menyediakan aplikasi QoS.
© COPYRIG
HT UPM
vii
ACKNOWLEDGEMENTS
First of all, I would like to express my greatest gratitude to ALLAH Almighty, for
His help and support during the course of life and the moment of truth.
I would like to express my appreciation and sincere gratitude to my
supervisor Dr. Makhfudzah Bt. Mokhtar for her continuous support, encouragement
and endless patience towards completing the research. These special thanks also
dedicated to my supervisory committee member; Dr. Siti Barrirah A. Anas and Dr.
Hilal A. Fadhil, for their motivations and encouragements. Working with all of you is
a good experience that could never be forgotten.
Secondly, I would like to thank all lab mates for their support, I would also like
to thank Dr Wan Azizan for her useful advices on my work. Further, I would like to
thank my friend and lab mate, Mr Saleh for his numerous help on my thesis. I really
appreciate him for the long discussions about my work. Also, I would like to thank
my close friends from my hometown for their supports and encouragements,
contacting me continuously during my study.
A huge appreciation to my beloved wife, Shawnim and to my daughter and son,
Yara and Yar; support and patience throughout the period of my study, your
continual support and patience made me strong in completing. Last but not least a
very special thanks and appreciation to my beloved mother and father, I would like to
thank the rest of my family, sisters and brothers who keep encouraging and
supporting me in whatever I do. Thank you very much.
© COPYRIG
HT UPM
viii
© COPYRIG
HT UPM
ix
This thesis was submitted to the Senate of Universiti Putra Malaysia and has been
accepted as fulfillment of the requirement for the degree of Master of Science. The
members of the Supervisory Committee were as follows:
Makhfudzah Bt Mokhtar, PhD
Senior Lecturer
Faculty of Engineering
Universiti Putra Malaysia
(Chairman)
Siti Barrirah Ahmad Anas , PhD
Senior Lecturer
Faculty of Engineering
Universiti Putra Malaysia
(Member)
Hilal Adnan Fadhil , PhD
Senior Lecturer
Faculty of Engineering
Universiti Perlis Malaysia
(Member)
BUJANG BIN KIM HUAT, PhD.
Professor and Dean
School of Graduate Studies
Universiti Putra Malaysia
Date:
© COPYRIG
HT UPM
x
DECLARATION
I declare that the thesis is my original work except for quotations and citations which
have been duly acknowledged. I also declare that it has not been previously, and is
not concurrently, submitted for any other degree at Universiti Putra Malaysia or at
any other institutions.
MAJID HAYAS KAKA
Date: 20 September 2013
© COPYRIG
HT UPM
xi
TABLE OF CONTENTS
Page
DEDICATION ii
ABSTRACT iii
ABSTRAK v
ACKNOWLEDGEMENTS vii
APPROVAL viii
DECLARATION x
TABLE OF CONTENTS xi
LIST OF TABLES xiv
LIST OF FIGURES xv
LIST OF ABBREVIATIONS xviii
CHAPTER
1 INTRODUCTION 1
1.1 Introduction 1
1.2 OCDMA Networks 2
1.3 Problem Statements 4
1.4 Research Objectives 6
1.5 Scope of Work 6
1.6 Research Contributions 8
1.7 Thesis Outline 8
2 LITERATURE REVIEW 10
2.1 Introduction 10
2.2 Optical Code Division Multiple Access (OCDMA) 10
2.3 Optical-CDMA Schemes 12
2.4 Coherent Optical CDMA Systems 13
2.4.1 Spectral Phase Coding (SPC) - OCDMA 13
2.4.2 Temporal Phase Coding (TPC) - OCDMA 14
2.5 Construction of Coherent OCDMA Codes 15
2.5.1 Maximal -Length Codes 16
2.5.2 Walsh -Hadamard Codes 16
2.5.3 Gold Codes 17
2.6 Incoherent Optical CDMA Systems 18
2.6.1 Spectral Amplitude Coding (SAC) 18
2.6.2 Temporal Spreading 19
© COPYRIG
HT UPM
xii
2.6.3 Wavelength-Hopping Time-Spreading 20
2.6.4 Spatial Coding 21
2.7 Construction of Incoherent OCDMA Codes 22
2.7.1 Optical Orthogonal Code (OOC) 23
2.7.2 Prime Codes 24
2.7.3 Hadamard Codes 25
2.7.4 Modified Quadratic Congruence (MQC) Code 26
2.7.5 Modified Frequency Hopping (MFH) Code 27
2.7.6 Random Diagonal (RD) Code 29
2.7.7 Khazani Syed (KS) Code 31
2.7.8 Dynamic Cyclic Shift (DCS) Code 32
2.8 Differentiated Quality of Service (QoS) Using SAC-OCDMA 33
2.9 Summary 34
3 CONSTRUCTION AND MATHEMATICAL MODEL FOR MS CODE 36
3.1 Introduction 36
3.2 Code Construction 37
3.3 Encoding/Decoding Process of MS Code 46
3.4 Relationships of MS Code Parameters 47
3.5 Mathematical Analysis of the Proposed Code Based on Two Different
Detection Techniques 48
3.5.1 AND Subtraction Detection (AD) Technique 48
3.5.2 Direct Decoding (DD) Technique 54
3.6 Mathematical Model of the proposed MS Code to Provide Service
Differentiation 57
4 RESULTS AND DISCUSSIONS 60
4.1 Introduction 60
4.2 Theoretical Analysis of MS Code 60
4.2.1 Effect of Number of Basic Codes (NB) on the System
Performance Using MS Code Based on Different Detection Techniques.61
4.2.2 Effect of Code Weight (W) on the System Performance Using
MS Code Based on DD Technique 64
4.2.3 Effect of Received Power ( ) on the MS System
Performance 65
4.2.4 MS Code Performance with Different System Capacity 66
4.2.5 Effect of Number of Users on System Performance for MS and
Other SAC-OCDMA Codes 68
4.3 Simulation Results of MS Code for SAC-OCDMA System 69
© COPYRIG
HT UPM
xiii
4.3.1 Simulation Setup of MS System Based on Different Detection
Techniques 69
4.3.2 MS Code Performance Analysis Based on AD Technique 71
4.3.3 MS Code Performance Analysis based on DD Technique 73
4.3.4 Effect of Number of MS Users on System Performance Based
on DD Technique 74
4.3.5 Performance Comparison of MS, KS and RD Codes in Terms of
Fiber Length Based on DD Technique 75
4.4 Comparison between Mathematical and Simulation Analysis 76
4.5 SAC-OCDMA System Configuration Based on MS Code for Different
QoS Application 77
5 CONCLUSIONS AND FUTURE WORKS 81
5.1 Conclusion 81
5.2 Future Works 83
REFERENCES 84
APPENDICES 92
BIODATA OF STUDENT 99
LIST OF PUBLICATIONS 100